Outcomes in post-ICU mechanical ventilation: a therapist-implemented weaning protocol

Aerosol particle dispersion in spontaneous breathing training of oxygen delivery tracheostomized patients on prolonged mechanical ventilation

BACKGROUND

Tracheostomized patients undergoing liberation from mechanical ventilation (MV) are exposed to the ambient environment through humidified air, potentially heightening aerosol particle dispersion. This study was designed to evaluate the patterns of aerosol dispersion during spontaneous breathing trials in such patients weaning from prolonged MV.

METHODS

Particle Number Concentrations (PNC) at varying distances from tracheostomized patients in a specialized weaning unit were quantified using low-cost particle sensors, calibrated against a Condensation Particle Counter. Different oxygen delivery methods, including T-piece and collar mask both with the humidifier or with a small volume nebulizer (SVN), and simple collar mask, were employed. The PNC at various distances and across different oxygen devices were compared using the Kruskal-Wallis test.

RESULTS

Of nine patients receiving prolonged MV, five underwent major surgery, and eight were successfully weaned from ventilation. PNCs at distances ranging from 30 cm to 300 cm showed no significant disparity (H(4) = 8.993, p = 0.061). However, significant differences in PNC were noted among oxygen delivery methods, with Bonferroni-adjusted pairwise comparisons highlighting differences between T-piece or collar mask with SVN and other devices.

CONCLUSION

Aerosol dispersion within 300 cm of the patient was not significantly different, while the nebulization significantly enhances ambient aerosol dispersion in tracheostomized patients on prolonged MV.

Managing the Chronically Ventilated Critically Ill Population

Advances in intensive care over the past few decades have significantly improved the chances of survival for patients with acute critical illness. However, this progress has also led to a growing population of patients who are dependent on intensive care therapies, including prolonged mechanical ventilation (PMV), after the initial acute period of critical illness. These patients are referred to as the "chronically critically ill" (CCI). CCI is a syndrome characterized by prolonged mechanical ventilation, myoneuropathies, neuroendocrine disorders, nutritional deficiencies, cognitive and psychiatric issues, and increased susceptibility to infections. It is associated with high morbidity and mortality as well as a significant increase in healthcare costs. In this article, we will review disease burden, outcomes, psychiatric effects, nutritional and ventilator weaning strategies as well as the role of palliative care for CCI with a specific focus on those requiring PMV.

Ventilator Weaning in Prolonged Mechanical Ventilation-A Narrative Review

Patients requiring mechanical ventilation (MV) beyond 21 days, usually referred to as prolonged MV, represent a unique group with significant medical needs and a generally poor prognosis. Research suggests that approximately 10% of all MV patients will need prolonged ventilatory care, and that number will continue to rise. Although we have extensive knowledge of MV in the acute care setting, less is known about care in the post-ICU setting. More than 50% of patients who were deemed unweanable in the ICU will be liberated from MV in the post-acute setting. Prolonged MV also presents a challenge in care for medically complex, elderly, socioeconomically disadvantaged and marginalized individuals, usually at the end of their life. Patients and their families often rely on ventilator weaning facilities and skilled nursing homes for the continuation of care, but home ventilation is becoming more common. The focus of this review is to discuss recent advances in the weaning strategies in prolonged MV, present their outcomes and provide insight into the complexity of care.

Weaning from Mechanical Ventilator in a Long-term Acute Care Hospital: A Retrospective Analysis

BACKGROUND

Prolonged Mechanical Ventilation (PMV) is associated with a higher cost of care and increased morbidity and mortality. Patients requiring PMV are referred mostly to Long-Term Acute Care (LTAC) facilities.

OBJECTIVE

To determine if protocol-driven weaning from mechanical ventilator by Respiratory Therapist (RT) would result in quicker weaning from mechanical ventilation, cost-effectiveness, and decreased mortality.

METHODS

A retrospective case-control study was conducted that utilized protocol-driven ventilator weaning by respiratory therapist (RT) as a part of the Respiratory Disease Certification Program (RDCP).

RESULTS

51 patients on mechanical ventilation before initiation of protocol-based ventilator weaning formed the control group. 111 patients on mechanical ventilation after implementation of the protocol formed the study group. Time to wean from the mechanical ventilation before the implementation of protocol-driven weaning by RT was 16.76 +/- 18.91 days, while that after the implementation of protocol was 7.67 +/- 6.58 days (p < 0.0001). Mortality proportion in patients after implementation of protocol-based ventilator weaning was 0.21 as compared to 0.37 in the control group (p=0.0153). The daily cost of patient care for the LTAC while on mechanical ventilation was $2200/day per patient while it was $ 1400/day per patient while not on mechanical ventilation leading to significant cost savings.

CONCLUSION

Protocol-driven liberation from mechanical ventilation in LTAC by RT can significantly decrease the duration of a mechanical ventilator, leading to decreased mortality and cost savings.

Difference in electromyographic activity between the trapezius muscle and other neck accessory muscles under an increase in inspiratory resistive loading in the supine position

The activity of the trapezius muscle is reportedly higher than that of other neck accessory muscles under a condition of increased inspiratory pressure in the standing position. The present study aimed to compare the activity of the trapezius muscle with those of the scalene and sternocleidomastoid muscles under a condition of increased inspiratory pressure in the supine position. This study included 40 subjects, and the muscle activity was measured using surface electromyography. Regarding the results, there was a significant difference in the muscle activity between the trapezius muscle and the scalene and sternocleidomastoid muscles (p = 0.003) in both men and women. Post-hoc analysis showed significant differences between trapezius and the other muscles. Moreover, there was no difference between the scalene and sternocleidomastoid muscles (p = 0.596). The increase in the change in electromyography activity of the muscle is greater in the trapezius muscle than in other muscles when the level of inspiratory pressure increases in the supine position.

Online Learning and Residents' Acquisition of Mechanical Ventilation Knowledge: Sequencing Matters

OBJECTIVE

Rapid advancements in medicine and changing standards in medical education require new, efficient educational strategies. We investigated whether an online intervention could increase residents' knowledge and improve knowledge retention in mechanical ventilation when compared with a clinical rotation and whether the timing of intervention had an impact on overall knowledge gains.

DESIGN

A prospective, interventional crossover study conducted from October 2015 to December 2017.

SETTING

Multicenter study conducted in 33 PICUs across eight countries.

SUBJECTS

Pediatric categorical residents rotating through the PICU for the first time. We allocated 483 residents into two arms based on rotation date to use an online intervention either before or after the clinical rotation.

INTERVENTIONS

Residents completed an online virtual mechanical ventilation simulator either before or after a 1-month clinical rotation with a 2-month period between interventions.

MEASUREMENTS AND MAIN RESULTS

Performance on case-based, multiple-choice question tests before and after each intervention was used to quantify knowledge gains and knowledge retention. Initial knowledge gains in residents who completed the online intervention (average knowledge gain, 6.9%; SD, 18.2) were noninferior compared with those who completed 1 month of a clinical rotation (average knowledge gain, 6.1%; SD, 18.9; difference, 0.8%; 95% CI, -5.05 to 6.47; p = 0.81). Knowledge retention was greater following completion of the online intervention when compared with the clinical rotation when controlling for time (difference, 7.6%; 95% CI, 0.7-14.5; p = 0.03). When the online intervention was sequenced before (average knowledge gain, 14.6%; SD, 15.4) rather than after (average knowledge gain, 7.0%; SD, 19.1) the clinical rotation, residents had superior overall knowledge acquisition (difference, 7.6%; 95% CI, 2.01-12.97;p = 0.008).

CONCLUSIONS

Incorporating an interactive online educational intervention prior to a clinical rotation may offer a strategy to prime learners for the upcoming rotation, augmenting clinical learning in graduate medical education.

Patient and Family Centered Actionable Processes of Care and Performance Measures for Persistent and Chronic Critical Illness: A Systematic Review

Supplemental Digital Content is available in the text.

To identify actionable processes of care, quality indicators, or performance measures and their evidence base relevant to patients with persistent or chronic critical illness and their family members including themes relating to patient/family experience.

Surface electromyographic evaluation of the neuromuscular activation of the inspiratory muscles during progressively increased inspiratory flow under inspiratory-resistive loading

This study aimed to evaluate neuromuscular activation in the scalene and sternocleidomastoid muscles using surface electromyography (EMG) during progressively increased inspiratory flow, produced by increasing the respiratory rate under inspiratory-resistive loading using a mask ventilator. Moreover, we attempted to identify the EMG inflection point (EMG^IP) on the graph, at which the root mean square (RMS) of the EMG signal values of the inspiratory muscles against the inspiratory flow velocity acceleration abruptly increases, similarly to the EMG anaerobic threshold (EMG^AT) reported during incremental-resistive loading in other skeletal muscles. We measured neuromuscular activation of healthy male subjects and found that the inspiratory flow velocity increased by approximately 1.6-fold. We successfully observed an increase in RMS that corresponded to inspiratory flow acceleration with ρ ≥ 0.7 (Spearman's rank correlation) in 17 of 27 subjects who completed the experimental protocol. To identify EMG^IP, we analyzed the fitting to either a straight or non-straight line related to the increasing inspiratory flow and RMS using piecewise linear spline functions. As a result, EMG^IP was identified in the scalene and sternocleidomastoid muscles of 17 subjects. We believe that the identification of EMG^IP in this study infers the existence of EMG^AT in inspiratory muscles. Application of surface EMG, followed by identification of EMG^IP, for evaluating the neuromuscular activation of respiratory muscles may be allowed to estimate the signs of the respiratory failure, including labored respiration, objectively and non-invasively accompanied using accessory muscles in clinical respiratory care.

[Prolonged weaning during early neurological and neurosurgical rehabilitation : S2k guideline published by the Weaning Committee of the German Neurorehabilitation Society (DGNR)]

Prolonged weaning of patients with neurological or neurosurgery disorders is associated with specific characteristics, which are taken into account by the German Society for Neurorehabilitation (DGNR) in its own guideline. The current S2k guideline of the German Society for Pneumology and Respiratory Medicine is referred to explicitly with regard to definitions (e.g., weaning and weaning failure), weaning categories, pathophysiology of weaning failure, and general weaning strategies. In early neurological and neurosurgery rehabilitation, patients with central of respiratory regulation disturbances (e.g., cerebral stem lesions), swallowing disturbances (neurogenic dysphagia), neuromuscular problems (e.g., critical illness polyneuropathy, Guillain-Barre syndrome, paraplegia, Myasthenia gravis) and/or cognitive disturbances (e.g., disturbed consciousness and vigilance disorders, severe communication disorders), whose care during the weaning of ventilation requires, in addition to intensive medical competence, neurological or neurosurgical and neurorehabilitation expertise. In Germany, this competence is present in centers of early neurological and neurosurgery rehabilitation, as a hospital treatment. The guideline is based on a systematic search of guideline databases and MEDLINE. Consensus was established by means of a nominal group process and Delphi procedure moderated by the Association of the Scientific Medical Societies in Germany (AWMF). In the present guideline of the DGNR, the special structural and substantive characteristics of early neurological and neurosurgery rehabilitation and existing studies on weaning in early rehabilitation facilities are examined.Addressees of the guideline are neurologists, neurosurgeons, anesthesiologists, palliative physicians, speech therapists, intensive care staff, ergotherapists, physiotherapists, and neuropsychologists. In addition, this guideline is intended to provide information to specialists for physical medicine and rehabilitation (PMR), pneumologists, internists, respiratory therapists, the German Medical Service of Health Insurance Funds (MDK) and the German Association of Health Insurance Funds (MDS). The main goal of this guideline is to convey the current knowledge on the subject of "Prolonged weaning in early neurological and neurosurgery rehabilitation".

Predictors and pattern of weaning and long-term outcome of patients with prolonged mechanical ventilation at an acute intensive care unit in North India

Objective

This study aimed to examine the clinical characteristics, weaning pattern, and outcome of patients requiring prolonged mechanical ventilation in acute intensive care unit settings in a resource-limited country.

Methods

This was a prospective single-center observational study in India, where all adult patients requiring prolonged ventilation were followed for weaning duration and pattern and for survival at both intensive care unit discharge and at 12 months. The definition of prolonged mechanical ventilation used was that of the National Association for Medical Direction of Respiratory Care.

Results

During the one-year period, 49 patients with a mean age of 49.7 years had prolonged ventilation; 63% were male, and 84% had a medical illness. The median APACHE II and SOFA scores on admission were 17 and 9, respectively. The median number of ventilation days was 37. The most common reason for starting ventilation was respiratory failure secondary to sepsis (67%). Weaning was initiated in 39 (79.5%) patients, with success in 34 (87%). The median weaning duration was 14 (9.5 - 19) days, and the median length of intensive care unit stay was 39 (32 - 58.5) days. Duration of vasopressor support and need for hemodialysis were significant independent predictors of unsuccessful ventilator liberation. At the 12-month follow-up, 65% had survived.

Conclusion

In acute intensive care units, more than one-fourth of patients with invasive ventilation required prolonged ventilation. Successful weaning was achieved in two-thirds of patients, and most survived at the 12-month follow-up.

Does the APACHE II score predict performance of activities of daily living in patients discharged from a weaning center?

INTRODUCTION

Data regarding the functional status of patients after prolonged mechanical ventilation are scarce, and little is known about its clinical predictors.

AIM

To investigate whether the Acute Physiology and Chronic Health Evaluation (APACHE) II score on admission may predict performance in activities of daily living on discharge from a weaning center.

MATERIAL AND METHODS

All consecutive patients admitted between January 1, 2012 and December 31, 2013 were enrolled (n = 130). During this period, 15 subjects died, and 115 were successfully discharged (34 women; 81 men). APACHE II was calculated based on the worst values taken during the first 24 hours after admission. On discharge, the Barthel Index (BI) and its extended version, the Early Rehabilitation Barthel Index (ERBI), were assessed.

RESULTS

Median BI was 20 points (IQR 5; 40), and ERBI was 20 points (-50; 40). There was no correlation between APACHE II and either BI (R = -0.07; p = 0.47) or ERBI (R = -0.07; p = 0.44). APACHE II predicted the need for assistance with bathing (AUROC = 0.833; p < 0.001), grooming (AUROC = 0.823; p < 0.001), toilet use (AUROC = 0.887; p < 0.001), and urination (AUROC = 0.658; p = 0.04). APACHE II had no impact on any ERBI items associated with ventilator weaning, including the need of further mechanical ventilation (AUROC = 0.534; p = 0.65) or tracheostomy (AUROC = 0.544; p = 0.42).

CONCLUSIONS

Although APACHE II cannot predict the overall functional status in patients discharged from a weaning center, it helps identify subjects who will need support with bathing, grooming, and toilet use. The APACHE II score is inadequate to predict performance in activities associated with further respiratory support.

A knowledge- and model-based system for automated weaning from mechanical ventilation: technical description and first clinical application

To describe the principles and the first clinical application of a novel prototype automated weaning system called Evita Weaning System (EWS). EWS allows an automated control of all ventilator settings in pressure controlled and pressure support mode with the aim of decreasing the respiratory load of mechanical ventilation. Respiratory load takes inspired fraction of oxygen, positive end-expiratory pressure, pressure amplitude and spontaneous breathing activity into account. Spontaneous breathing activity is assessed by the number of controlled breaths needed to maintain a predefined respiratory rate. EWS was implemented as a knowledge- and model-based system that autonomously and remotely controlled a mechanical ventilator (Evita 4, Dräger Medical, Lübeck, Germany). In a selected case study (n = 19 patients), ventilator settings chosen by the responsible physician were compared with the settings 10 min after the start of EWS and at the end of the study session. Neither unsafe ventilator settings nor failure of the system occurred. All patients were successfully transferred from controlled ventilation to assisted spontaneous breathing in a mean time of 37 ± 17 min (± SD). Early settings applied by the EWS did not significantly differ from the initial settings, except for the fraction of oxygen in inspired gas. During the later course, EWS significantly modified most of the ventilator settings and reduced the imposed respiratory load. A novel prototype automated weaning system was successfully developed. The first clinical application of EWS revealed that its operation was stable, safe ventilator settings were defined and the respiratory load of mechanical ventilation was decreased.

Extending the ABCDE bundle to the post-intensive care unit setting

A recently proposed interprofessional, evidence-based, multicomponent approach to mitigating the effects of intensive care unit (ICU)-acquired delirium and weakness has the potential to radically transform the way care is delivered to older adults requiring sedation, mechanical ventilation, or both. The Awakening and Breathing Coordination, Delirium Monitoring and Management, and Early Mobility (ABCDE) bundle empowers members of the interdisciplinary ICU team to implement the best available evidence regarding mechanical ventilation, sedation, weakness, and delirium in a safe, effective, and patient-centered manner. Considering that critically ill older adults are cared for in a number of different settings during the course of hospitalization and recovery, the purpose of this article is to explore the rationale and possible benefits of extending the ABCDE bundle into the post-ICU setting. We provide a case study that illustrates how ABCDE bundle adoption could be the key to improving the quality of care provided to seriously ill older adults in the ICU and beyond.

Efeitos da fisioterapia no desmame da ventilação mecânica

INTRODUÇÃO: A Fisioterapia vem atuando com o objetivo de reduzir falhas no desmame da ventilação mecânica (VM) que podem repercutir em desfechos desfavoráveis para o paciente. OBJETIVO: Avaliar os efeitos da fisioterapia no desmame da VM. MATERIAIS E MÉTODOS: Estudo transversal e controlado com pacientes adultos. A formação dos grupos estudados foi resultado de dois períodos ocorridos em uma UTI; em determinado período, a unidade contou com a presença de um profissional de Fisioterapia, em outro, não teve a presença desse profissional por razões administrativas. Registraram-se os resultados do desmame por meio de coleta diária de informações. Foram estudados 50 pacientes, 31 fizeram fisioterapia (grupo fisioterapia, GF) e 19 não fizeram (grupo controle, GC). O GF realizou dois atendimentos diários (quarenta minutos cada), composto das técnicas: compressão do tórax, hiperinsuflação manual, aspiração traqueal e de vias aéreas, movimentação e condução do desmame. O GC recebeu tratamento médico usual. RESULTADOS: Observou-se no GF e GC, respectivamente: sucesso no desmame - 71% (22) e 21% (4) (p = 0,001); tempo de VM - 152 ± 142 e 414 ± 344 horas (p = 0,04); tempo de desmame: 13 ± 48 e 140 ± 122 horas (p < 0,0001); tempo de internação na UTI - 338 ± 192 e 781 ± 621 horas (p = 0,007); tempo de internação hospitalar - 710 ± 628 e 1108 ± 720 horas (p = 0,058); mortalidade: 35% (11) e 47% (9) (p = 0,41). CONCLUSÃO: A fisioterapia esteve associada ao aumento do sucesso no desmame, à redução do tempo de desmame, tempo de VM e de internação na UTI. Não houve diferença no tempo de internação hospitalar e na mortalidade.

[Weaning from prolonged mechanical ventilation in neurological weaning units: an evaluation of the German Working Group for early Neurorehabilitation]

BACKGROUND

A significant proportion of patients with long-term mechanical ventilation (MV) and difficult or prolonged weaning suffer from primary or secondary neurological conditions and concomitant functional disorders, in addition to respiratory problems. Therefore, these patients are treated in neurological weaning departments.

MATERIAL AND METHODS

Using a questionnaire members of the German Working Group for early neurorehabilitation were interviewed with respect to the structure of weaning facilities, weaning strategies, patient characteristics and treatment outcome of patients admitted for weaning in 2009.

RESULTS

In the year 2009 a total of 1,486 patients were admitted to 7 participating neurological weaning units. The primary diagnosis was a neurological condition in 97.5% of the patients. In 62.9% of the patients the neurological condition was considered to be primarily responsible for the MV, 22.8% demonstrated pulmonary factors and for 3.0% a cardiac condition was determined to be decisive. In 5.0% of the patients it was not possible to ascertain a single cause or factor. Weaning was successful in 69.8% of all cases, 64.9% (965 patients) were released from the facility without MV, 274 patients (18.4%) were released with MV, 61.3% of these (168 patients) were referred to other rehabilitation facilities or into the care of the family physician and 38.7% (106 patients) were transferred to other hospitals due to special medical problems. The total mortality rate was 16.6% (247 patients deceased).

CONCLUSIONS

In this first comprehensive evaluation of German neurological weaning centers for patients with long-term MV, structures and treatment outcomes were compared with recent results from the literature.

Protocol-directed versus physician-directed weaning from noninvasive ventilation: the impact in chronic obstructive pulmonary disease patients

BACKGROUND

Noninvasive ventilation (NIV), a technique widely used in intensive care units (ICUs), eliminates the need for many patients in respiratory failure to undergo intubation. However, few articles have described how to wean patients from NIV. Herein, we put forward a protocol to be performed by respiratory therapists to wean patients from NIV.

METHODS

A prospective, randomized, controlled trial was performed in a respiratory ICU of a teaching hospital. Respiratory therapists screened patients daily. In the protocol-directed weaning group, the weaning attempt was initiated according to the protocol. In the physician-directed weaning group, the weaning attempt was initiated according to physicians' orders.

RESULTS

At randomization, patients in the two groups had similar clinical characteristics. A total of 73 patients were successfully weaned from NIV (37 in the protocol-directed group and 36 in the physician-directed group). The preponderance of them (64%) was chronic obstructive pulmonary disease patients. Compared with physician-directed weaning, protocol-directed weaning reduced the duration of NIV (4.4 ± 2.5 days vs. 2.6 ± 1.5 days, respectively, p < 0.001) and the duration of the ICU stay (8.1 ± 5.5 days vs. 5.8 ± 2.7 days, respectively, p = 0.02). In the protocol-directed group, the successful weaning rate was 57%, 27%, 13%, 0%, and 3% on the 1st, 2nd, 3rd, 4th, and 5th days after randomization, respectively.

CONCLUSIONS

Protocol-directed weaning reduces the duration of NIV and the duration of the ICU stay.

LEVEL OF EVIDENCE

II.

Testing the prognostic value of the rapid shallow breathing index in predicting successful weaning in patients requiring prolonged mechanical ventilation

OBJECTIVE

The study objective was to assess the prognostic value of the rapid shallow breathing index (RSBI) in predicting successful weaning of patients from prolonged mechanical ventilation (PMV) in long-term acute care (LTAC) facilities. The RSBI predicts successful ventilator weaning in acutely ill patients. However, its value in PMV is unclear.

METHODS

A retrospective cohort study of patients receiving PMV in LTAC facilities was performed. RSBI was measured daily, with weaning per protocol. Initial, mean, and final RSBI; RSBI ≤ 105; rate of change; and variability were assessed.

RESULTS

Twenty-five of 52 patients were weaned from PMV. Only the mean RSBI and the RSBI on the last day of weaning predicted success (78.7 ± 14.2 vs 99.3 ± 30.2, P = .007; 71.7 ± 31.2 vs 123.3 ± 92.5, P = .005, respectively). RSBI variability and rate of change were different between groups (coefficient of variation, .37 ± .12 vs .51 ± .30, P = .02, rate of change: -3.40 ± 9.40 vs 4.40 ± 11.1 RSBI points/day, P = .005, weaned vs failed).

CONCLUSION

Although isolated RSBI measurements do not predict successful weaning from PMV, RSBI trends may have prognostic value.

Automatic control of pressure support for ventilator weaning in surgical intensive care patients

RATIONALE

Despite its ability to reduce overall ventilation time, protocol-guided weaning from mechanical ventilation is not routinely used in daily clinical practice. Clinical implementation of weaning protocols could be facilitated by integration of knowledge-based, closed-loop controlled protocols into respirators.

OBJECTIVES

To determine whether automated weaning decreases overall ventilation time compared with weaning based on a standardized written protocol in an unselected surgical patient population.

METHODS

In this prospective controlled trial patients ventilated for longer than 9 hours were randomly allocated to receive either weaning with automatic control of pressure support ventilation (automated-weaning group) or weaning based on a standardized written protocol (control group) using the same ventilation mode. The primary end point of the study was overall ventilation time.

MEASUREMENTS AND MAIN RESULTS

Overall ventilation time (median [25th and 75th percentile]) did not significantly differ between the automated-weaning (31 [19-101] h; n = 150) and control groups (39 [20-118] h; n = 150; P = 0.178). Patients who underwent cardiac surgery (n = 132) exhibited significantly shorter overall ventilation times in the automated-weaning (24 [18-57] h) than in the control group (35 [20-93] h; P = 0.035). The automated-weaning group exhibited shorter ventilation times until the first spontaneous breathing trial (1 [0-15] vs. 9 [1-51] h; P = 0.001) and a trend toward fewer tracheostomies (17 vs. 28; P = 0.075).

CONCLUSIONS

Overall ventilation times did not significantly differ between weaning using automatic control of pressure support ventilation and weaning based on a standardized written protocol. Patients after cardiac surgery may benefit from automated weaning. Implementation of additional control variables besides the level of pressure support may further improve automated-weaning systems. Clinical trial registered with www.clinicaltrials.gov (NCT 00445289).

The factors which influence nurses when weaning patients from mechanical ventilation: findings from a qualitative study

The aim of the study was to describe the factors that influence critical care nurses when deciding to wean patients from mechanical ventilation. The study adopted a qualitative methodology, using semi-structured interviews and a vignette. An invited sample of critical care nurses (n=24) from one Irish intensive care unit was employed. Each nurse was interviewed once and a vignette was used to structure the interview questioning. The findings were analysed using thematic content analysis. Six major themes influencing nurses' decision to wean emerged, as follows: physiological influences; clinical reassessment and decision making; the nurse's experience, confidence and education; the patient's medical history and current ventilation; the intensive care working environment; and use of protocols. The findings highlight the complex nature of weaning patients from mechanical ventilation and the major role of the nurse in this process.

Renal replacement therapy in prolonged mechanical ventilation patients with renal failure in Taiwan

BACKGROUND

Renal failure requiring renal replacement therapy (RRT) is associated with a high mortality rate in intensive care unit (ICU) patients. Little information is available on the outcomes of patients having prolonged mechanical ventilation (PMV) in addition to RRT. The purpose of this study was to investigate the impact of RRT in PMV patients.

METHODS

This was an observational, retrospective study in the 24-bed respiratory care center (RCC) of Chang Gung Memorial Hospital, Taiwan, between May 2001 and April 2007. The end points were weaning rate and survival rate at the RCC.

RESULTS

Of the 1301 RCC patients, 157 patients (13.7%) underwent RRT. The RRT patients had lower successful weaning rate (39.5% vs 58.4%, P < .001) and RCC survival rate (45.9% vs 71.9%, P < .001) compared with without-RRT patients. The successful weaning rates of end-stage renal disease (ESRD) patients, patients with RRT initiated at the ICU and continued at RCC, and patients whose RRT was initiated at the RCC were 49.2%, 39.1%, and 22.2%, respectively. The RCC survival rates were 50.8%, 47.8%, and 29.6%, respectively. The odds ratios of successful weaning rate and survival rate were 0.295 (95% confidence interval, 0.105-0.833; P = .021) and 0.407 (95% confidence interval, 0.155-1.021; P = .069) for patients whose RRT was initiated at the RCC vs ESRD patients.

CONCLUSION

The present study demonstrates that the need for RRT had a negative impact on weaning and mortality in PMV patients compared with patients without RRT. Patients who had RRT initiated at the RCC had a significantly lower weaning rate compared with ESRD patients.

Survival in Patients Receiving Prolonged Ventilation: Factors that Influence Outcome

Background:

Prolonged mechanical ventilation is increasingly common. It is expensive and associated with significant morbidity and mortality. Our objective is to comprehensively characterize patients admitted to a Ventilator Rehabilitation Unit (VRU) for weaning and identify characteristics associated with survival.

Methods:

182 consecutive patients over 3.5 years admitted to Temple University Hospital (TUH) VRU were characterized. Data were derived from comprehensive chart review and a prospectively collected computerized database. Survival was determined by hospital records and social security death index and mailed questionnaires.

Results:

Upon admission to the VRU, patients were hypoalbuminemic (albumin 2.3 ± 0.6 g/dL), anemic (hemoglobin 9.6 ± 1.4 g/dL), with moderate severity of illness (APACHE II score 10.7 + 4.1), and multiple comorbidities (Charlson index 4.3 + 2.3). In-hospital mortality (19%) was related to a higher Charlson Index score (P = 0.006; OR 1.08–1.6), and APACHE II score (P = 0.016; OR 1.03–1.29). In-hospital mortality was inversely related to admission albumin levels (P = 0.023; OR 0.17–0.9). The presence of COPD as a comorbid illness or primary determinant of respiratory failure and higher VRU admission APACHE II score predicted higher long-term mortality. Conversely, higher VRU admission hemoglobin was associated with better long term survival (OR 0.57–0.90; P = 0.0006).

Conclusion:

Patients receiving prolonged ventilation are hypoalbuminemic, anemic, have moderate severity of illness, and multiple comorbidities. Survival relates to these factors and the underlying illness precipitating respiratory failure, especially COPD.

An analysis of clinical outcomes and costs of a long term acute care hospital

OBJECTIVE

Compare clinical outcomes and costs in a study group of long-term acute care hospital (LTCH) patients with a control group of LTCH-eligible patients in an acute care hospital. LTCHs were created to provide post-acute care services not available at other post-acute settings. This is based on the premise that these patients would otherwise have stayed at acute care hospitals as high-cost outliers. The LTCH hospital is intended to deliver care to patients more efficiently, however, there are little documented clinical and financial data regarding the comparative clinical outcomes and costs for patients.

METHODS

Retrospective medical and billing record review of patients from the following groups: (1) LTCH study comprising patients admitted directly from an acute care hospital to the study LTCH and discharged from the LTCH from September 2004 through August 2006; (2) a control group of LTCH-eligible, medically complex patients treated and discharged from an acute care hospital in FY 2002. The control group was selected from approximately 500 patients who had at least one of the ten most common principle diagnosis DRGs of the study LTCH with >30-day length of stay at the referring hospital and met NALTH admitting guidelines.

RESULTS

Discharge disposition is an important outcome measure of the quality of care of medically complex patients. The in-hospital mortality rate trended lower and home discharge was 3 times higher for the LTCH study group than for the control group. As a possible result, SNF discharge of LTCH patients was approximately half that of the control group. Both mean patient cost per day and mean total cost per patient were significantly higher in the control group than in the LTCH study group.

CONCLUSIONS

The patients in the LTCH study group had both better clinical outcomes and lower cost of care than the control group.

Chronic critical illness

Although advances in intensive care have enabled more patients to survive an acute critical illness, they also have created a large and growing population of chronically critically ill patients with prolonged dependence on mechanical ventilation and other intensive care therapies. Chronic critical illness is a devastating condition: mortality exceeds that for most malignancies, and functional dependence persists for most survivors. Costs of treating the chronically critically ill in the United States already exceed $20 billion and are increasing. In this article, we describe the constellation of clinical features that characterize chronic critical illness. We discuss the outcomes of this condition including ventilator liberation, mortality, and physical and cognitive function, noting that comparisons among cohorts are complicated by variation in defining criteria and care settings. We also address burdens for families of the chronically critically ill and the difficulties they face in decision-making about continuation of intensive therapies. Epidemiology and resource utilization issues are reviewed to highlight the impact of chronic critical illness on our health care system. Finally, we summarize the best available evidence for managing chronic critical illness, including ventilator weaning, nutritional support, rehabilitation, and palliative care, and emphasize the importance of efforts to prevent the transition from acute to chronic critical illness. As steps forward for the field, we suggest a specific definition of chronic critical illness, advocate for the creation of a research network encompassing a broad range of venues for care, and highlight areas for future study of the comparative effectiveness of different treatment venues and approaches.

Frequency of ventilator-associated pneumonia with 3-day versus 7-day ventilator circuit changes

BACKGROUND

Ventilator-associated pneumonia (VAP) is a common clinical problem. Previous studies involving adult patient cohorts have assessed various risk factors associated with VAP, including ventilator circuit changes. The objective of this study was to examine the incidence of and risk factors associated with VAP, particularly 3-day versus 7-day ventilator circuit changes, in a pediatric intensive care unit (PICU).

METHODS

This was a cohort observational study. Patients hospitalized in the PICU at Chang Gung Children's Hospital between November 2003 and September 2004 were enrolled. Investigators and critical-care specialists evaluated baseline characteristics, incidence of VAP, and related variables from PICU admission until discharge or death.

RESULTS

Of 397 patients initially enrolled, 96 (aged 11-60 months) were available for statistical analysis and were assigned into two groups according to timing of ventilator circuit change: 3-day (n = 46) and 7-day circuit change (n = 50). No statistically significant differences were observed for VAP incidence (13% vs. 16%, p = 0.68) or hospital mortality (22% vs. 36%, p = 0.14) for 3-day versus 7-day circuit change. Incidence of VAP per 1000 ventilation days was 10.75 and 8.41 for 3-day and 7-day circuit change, respectively. Univariate analysis indicated statistical significance for the duration of mechanical ventilation (10.17 +/- 16.63 days vs. 18.20 +/- 14.99 days, p < 0.001), length of stay in PICU (22.30 +/- 20.48 days vs. 37.22 +/- 36.79 days, p = 0.0069) and presence of enteral nutrition [7 (15.22%) vs. 23 (46.0%), p = 0.0012].

CONCLUSION

Weekly circuit change does not contribute to increased rates of VAP in pediatric patients. Long-term studies evaluating risk factors in larger pediatric patient populations are warranted for further conclusive recommendations.

Outcomes of hemodialysis patients in a long-term care hospital setting: a single-center study

BACKGROUND

Long-term care hospitals (LTCHs) provide intermediary care after an acute-care hospitalization and usually furnish care to patients with complex medical problems. Outcomes of hemodialysis patients admitted to LTCHs, which includes patients with either end-stage renal disease (ESRD) or acute kidney injury (AKI) requiring dialysis therapy, are not known.

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

All consecutive hemodialysis patients admitted to an LTCH.

PREDICTORS

Demographic characteristics, comorbid and laboratory variables, ESRD, and AKI status during LTCH stay.

OUTCOMES

Disposition from LTCHs was classified as discharge to home, nursing home, death in LTCH or hospice care, and re-admission to the hospital. In patients with AKI, renal recovery was defined as discontinuation of dialysis therapy before meeting disposition outcomes.

RESULTS

96 of 206 (46.6%) patients had ESRD, whereas 110 of 206 (53.3%) developed AKI requiring dialysis therapy during the acute-care hospitalization. 63 of 206 (31%) were discharged to home, 11 of 206 (5.4%) died or transferred to hospice, 81 of 206 (40%) went to a nursing home, and 49 of 206 (24%) were re-admitted to a hospital; mortality after re-admission was 32%. Older age (OR, 0.96; 95% CI, 0.93-0.98), diabetes mellitus (OR, 0.45; 95% CI, 0.23-0.94), number of re-admissions to the hospital (OR, 0.38; 95% CI, 0.18-0.78), aminoglycoside use (OR, 0.16; 95% CI, 0.04-0.64), and duration of hospitalization before LTCH admission (OR, 0.96; 95% CI, 0.94-0.99) were associated with lower odds of discharge to home. Of 110 patients with AKI requiring dialysis therapy, 30% (33 patients) discontinued dialysis therapy, whereas 70% were deemed to have ESRD on discharge.

LIMITATIONS

Retrospective observational study.

CONCLUSIONS

Most dialysis patients at LTCHs are either re-admitted to acute-care hospitals or require nursing home placement. Only 30% of patients with AKI recover sufficiently to discontinue dialysis therapy, whereas 70% are deemed to have ESRD.

Terminal withdrawal of mechanical ventilation at a long-term acute care hospital: comparison with a medical ICU

BACKGROUND

Failure to wean from prolonged mechanical ventilation (MV) is common in long-term acute care hospitals (LTACHs), but the process of terminal withdrawal of MV in LTACHs is not well described. We compared terminal withdrawal of MV at an LTACH with that in a medical ICU (MICU).

METHODS

A retrospective medical chart review was done of all patients undergoing terminal withdrawal of MV in an LTACH (n = 30) and in a MICU (n = 74) over a 2-year period.

RESULTS

The decision to withdraw MV was more likely initiated by patient or family in the LTACH and by medical staff in the MICU (p < 0.0001). Social workers, pastoral care, and hospital administration were more likely to participate in the withdrawal process at the LTACH compared with the MICU (p < 0.05). Time from initiation of MV to orders for do not resuscitate, comfort measures only, or withdrawal of MV was significantly greater in the LTACH (weeks) compared with the MICU (days) (p < 0.05). The dose of benzodiazepines given during the final 24 h of life was greater in the MICU as compared with the LTACH (p < 0.05). Narcotic and benzodiazepine use in the hour before or after withdrawal of MV did not differ between the two groups. COPD and pneumonia were the most common causes of death among patients undergoing withdrawal of MV at the LTACH, as opposed to septic shock in the MICU (p < 0.05).

CONCLUSIONS

Terminal withdrawal of MV in the LTACH differs from that in the MICU with regard to decision making, benzodiazepine use, and cause of death.

Predictors of successful weaning from prolonged mechanical ventilation in Taiwan

BACKGROUND

For adult patients on prolonged mechanical ventilation (PMV, >/=21 days), successful weaning has been attributed to various factors. The purpose of this study was to describe patient outcomes, weaning rates and factors in successful weaning at a hospital-based respiratory care center (RCC) in Taiwan.

METHODS AND RESULTS

This was a retrospective observational study performed in a 24-bed RCC over six years. A total of 1307 patients on PMV were included in the study. The overall survival rate was 62%. Fifty-six percent of patients were successfully weaned. Unsuccessfully weaned patients had higher MICU transfer rates, higher Acute Physiology and Chronic Health Evaluation II scores, longer duration of RCC stay, higher rates of being bed-ridden prior to admission, increased hemodialysis rates, higher modified Glasgow Coma Scale scores, higher rapid shallow breathing index, lower inspiratory pressure at residual volume (PImax) and lower blood urea nitrogen (BUN) and creatinine levels. Factors found to be associated with unsuccessful weaning were length of RCC stay (OR=1.04, P<0.001), modified GCS score (OR=0.93, P<0.046), PImax (OR=0.97, P<0.001), serum albumin concentration (OR=0.62, P<0.023) and BUN level (OR=1.01, P<0.002).

CONCLUSION

High rates of ventilator independence can be achieved in an RCC setting as an alternative to ICU care. Factors associated with unsuccessful weaning included longer duration of RCC stay, elevated BUN levels and lower modified GCS scores, serum albumin and PImax levels.

Decannulation Following Tracheostomy for Prolonged Mechanical Ventilation

Background: We examined the process of decannulation following tracheostomy in patients transferred to a long-term acute care (LTAC) hospital for weaning from prolonged mechanical ventilation (PMV). Methods: A retrospective chart review of 135 patients. Results: Decannulation was successful in 35% of patients a median of 45 days (IQR, 32-76) following tracheostomy. Patients who failed decannulation had a tracheostomy tube placed earlier (14 days; IQR 11-18 vs. 18 days; IQR 14-30, P = .04) and had a shorter length of stay at the acute facility (20 days; IQR, 16-23 vs. 31 days; IQR, 24-45, P = .003) compared with patients who were decannulated. Length of stay and cost of care at the LTAC did not differ with decannulation status. At 3.5 years, 35% (47/135) of all patients and 62% (29/47) of decannulated patients were alive. Conclusions: Decannulation was achieved in 35% of patients transferred to an LTAC for weaning from prolonged mechanical ventilation.

Determinants of long-term mortality after prolonged mechanical ventilation

STUDY OBJECTIVES

The poor long-term survival of patients requiring prolonged mechanical ventilation may be due to potentially modifiable factors. We therefore sought to assess the early determinants of long-term survival after discharge from a specialized respiratory unit.

METHODS

Eighty of 113 patients (71%) admitted to a respiratory care unit from June 2001 to August 2003 survived to discharge. Mortality outcomes and dates of death were determined by review of the records and survey in April 2005 of a national Death Master File. Potential determinants of survival after discharge were collected during the admission to the unit.

RESULTS

Fifty-five percent of patients died within the first year after discharge. Age of 65 years or older, sacral ulcers, a serum creatinine >124 micromol/L, and failure to wean were each individually associated with shorter survival. Age, skin integrity, and wean status on discharge remained independent determinants of survival in a multivariable analysis. In a post-hoc analysis, chronic irreversible neurologic diseases were also independently associated with poor long-term survival.

CONCLUSIONS

Mortality after discharge from a respiratory care unit is high. Interventions that may favorably impact long-term survival in these patients could target the modifiable factors identified, including measures that facilitate weaning and prevent or treat renal dysfunction and skin breakdown.

Protocol-driven ventilator weaning: reviewing the evidence

Though seminal clinical trials have identified efficacious methods of liberating patients from mechanical ventilation (ie, weaning), this knowledge is not applied often by physicians in routine practice. Weaning protocols are a strategies by which research results can be translated effectively and efficiently into clinical practice, but results of clinical trials evaluating weaning protocols have not been uniform, and controversy continues to surround this important area in critical care medicine. This article reviews the rationale for and against the routine use of weaning protocols and highlights informative details of many clinical trials that have evaluated such protocols.

Successful weaning predictors in a respiratory care center in Taiwan

Respiratory care centers (RCCs) provide effective care for patients who have been in intensive care and have undergone prolonged mechanical ventilation. Between February 2002 and December 2005, 891 patients who met the admission criteria of RCCs were referred to our RCC at Kaohsiung Medical University Hospital in southern Taiwan for attempted weaning. We recorded demographic and clinical data, including variables identified previously as predictive of weaning success among highly selected populations. The common causes of respiratory failure at RCC admission were neuromuscular disease (29.2%), pneumonia (27.5%), cancer (18.0%), cardiovascular disease (10.1%), sepsis (5.7%) and post-surgery (1.6%). The percentage of patients successfully weaned was 40.2%, while 59.8% remained dependent on ventilators. In a stepwise multivariate logistic regression analysis, significant predictors of weaning success included neuromuscular disease (odds ratio [OR], 2.64), APACHE II score (OR, 0.93) and blood urea nitrogen level at RCC admission (OR, 0.99). The results could be helpful in the accreditation of medical care quality and may provide guidelines for future research and education programs.

Development and simultaneous application of multiple care protocols in critical care: a multicenter feasibility study

OBJECTIVE

To test the feasibility of and interactions among three software-driven critical care protocols.

DESIGN

Prospective cohort study.

SETTING

Intensive care units in six European and American university hospitals.

PATIENTS

174 cardiac surgery and 41 septic patients.

INTERVENTIONS

Application of software-driven protocols for cardiovascular management, sedation, and weaning during the first 7 days of intensive care.

MEASUREMENTS AND RESULTS

All protocols were used simultaneously in 85% of the cardiac surgery and 44% of the septic patients, and any one of the protocols was used for 73 and 44% of study duration, respectively. Protocol use was discontinued in 12% of patients by the treating clinician and in 6% for technical/administrative reasons. The number of protocol steps per unit of time was similar in the two diagnostic groups (n.s. for all protocols). Initial hemodynamic stability (a protocol target) was achieved in 26+/-18 min (mean+/-SD) in cardiac surgery and in 24+/-18 min in septic patients. Sedation targets were reached in 2.4+/-0.2h in cardiac surgery and in 3.6 +/-0.2h in septic patients. Weaning protocol was started in 164 (94%; 154 extubated) cardiac surgery and in 25 (60%; 9 extubated) septic patients. The median (interquartile range) time from starting weaning to extubation (a protocol target) was 89 min (range 44-154 min) for the cardiac surgery patients and 96 min (range 56-205 min) for the septic patients.

CONCLUSIONS

Multiple software-driven treatment protocols can be simultaneously applied with high acceptance and rapid achievement of primary treatment goals. Time to reach these primary goals may provide a performance indicator.

Transferring critically ill patients out of hospital improves the standardized mortality ratio: a simulation study

BACKGROUND

Transferring critically ill patients to other acute care hospitals may artificially impact benchmarking measures. We sought to quantify the effect of out-of-hospital transfers on the standardized mortality ratio (SMR), an outcome-based measure of ICU performance.

METHODS

We performed a cohort study and Monte Carlo simulation using data from 85 ICUs participating in the acute physiology and chronic health evaluation (APACHE) clinical information system from 2002 to 2003. The SMR (observed divided by expected hospital mortality) was calculated for each ICU using APACHE IV risk adjustment. A set number of patients was randomly assigned to be transferred out alive rather than experience their original outcome. The SMR was recalculated, and the mean simulated SMR was compared to the original.

RESULTS

The mean (+/- SD) baseline SMR was 1.06 +/- 0.19. In the simulation, increasing the number of transfers by 2% and 6% over baseline decreased the SMR by 0.10 +/- 0.03 and 0.14 +/- 0.03, respectively. At a 2% increase, 27 ICUs had a decrease in SMR of > 0.10, and two ICUs had a decrease in SMR of > 0.20. Transferring only one additional patient per month was enough to create a bias of > 0.1 in 27 ICUs.

CONCLUSIONS

Increasing the number of acute care transfers by a small amount can significantly bias the SMR, leading to incorrect inference about ICU quality. Sensitivity to the variation in hospital discharge practices greatly limits the use of the SMR as a quality measure.

Therapist driven protocols: a look back and moving into the future

Therapist-driven protocols have been shown to decrease the duration of mechanical ventilation, reduce cost, length of stay, and improve the rate of weaning when compared with physician-directed weaning. This article describes protocols used at the author's institution. It describes how the respiratory therapy service interacts with other services within the hospital to provide the optimal outcome for the patient.

Ventilator-Dependent Survivors of Catastrophic Illness Transferred to 23 Long-term Care Hospitals for Weaning From Prolonged Mechanical Ventilation

STUDY OBJECTIVES

This multicenter study was undertaken to characterize the population of ventilator-dependent patients admitted to long-term care hospitals (LTCHs) for weaning from mechanical ventilation.

DESIGN

Observational study with concurrent data collection. Characteristics of the LTCHs were also surveyed.

SETTING

Twenty-three LTCHs in the United States.

PATIENTS

Consecutive ventilator-dependent patients admitted over a 1-year period: March 1, 2002, to February 28, 2003.

RESULTS

A total of 1,419 patients were enrolled in the Ventilation Outcomes Study. Median age of the patients was 71.8 years old (range, 18 to 97.7 years), with an equal gender distribution. The premorbid domicile was home or assisted living in 86.5%; "good" premorbid functional status (Zubrod score 0-2) was assessed in 77%. There was a history of smoking in 59% (mean, 57 +/- 42 pack-years [+/- SD]); premorbid diagnoses averaged 2.6 per patient. Patients came to the LTCH after mean of 33.8 +/- 29 days at the transferring hospital; mean time to tracheotomy was 15.0 +/- 10 days. A medical illness led to ventilator dependency in 60.8% of patients; a surgical procedure led to ventilatory dependency in 39.2%. On admission to the LTCH, the median acute physiology score of APACHE (acute physiology and chronic health evaluation) III was 35 (range, 4 to 115); > 90% of patients had at least three penetrating indwelling tubes/catheters; 42% of patients had stage 2 or higher pressure ulceration.

CONCLUSIONS

This is the first multicenter study to characterize ventilator-dependent survivors of catastrophic illness admitted to the post-ICU venue of LTCHs for weaning from prolonged mechanical ventilation (PMV). Overall, our findings suggest that ventilator-dependent patients admitted to LTCHs for weaning will continue to require considerable medical interventions and treatments, owing to the burden of acute-on-chronic diseases resulting in PMV.

Experience with a step-down respiratory care center at a tertiary referral medical center in Taiwan

OBJECTIVE

The aim of the study was to describe the outcome of patients after 1 year's implementation of an integrated delivery system for respiratory care mandated by the National Health Insurance Bureau in Taiwan.

DESIGN

A retrospective observational study was conducted in a step-down respiratory care center (RCC).

PATIENTS

Patients included adults receiving prolonged mechanical ventilation (> or =21 days).

MEASUREMENTS AND MAIN RESULTS

A total of 224 cases were available for review; 108 (48.2%) patients were successfully weaned. Those who failed weaning had a longer stay in the intensive care unit and RCC (25.1 vs 20.9 and 31.4 vs 18.6 days, P < .05), but there were no differences in the patients' ages (74.3 vs 70.4 years, P = .17) or the Simplified Acute Physiology Score II (52 vs 46.9, P = .18) before admission to the RCC. After discharge from the RCC, only 4.9% of the patients still on a ventilator were weaned within 1 year. Patients who failed weaning in the RCC had a shorter overall survival (5.2 vs 10.4 months, P < .05) and a lower 1-year survival (23.6% vs 44.6%, P < .05).

CONCLUSION

Patients admitted to the RCC were still critically ill. Patients who failed weaning in the RCC had had a longer intensive care unit and RCC stay and a worse outcome after leaving the RCC.

Issues in weaning from mechanical ventilation: literature review

AIM

The aim of this paper is to raise questions on the effect of skill mix and organizational structure on weaning from mechanical ventilation.

BACKGROUND

Mechanical ventilation is an essential life-saving technology. There are, however, numerous associated complications that influence the morbidity and mortality of patients receiving intensive care. Therefore, it was essential to use the safest and most effective form of ventilation for the shortest possible duration. Because of the potential complications and costs of mechanical ventilation, research to date have focused on accurate weaning readiness assessment, methods and organizational aspects that influence the weaning process.

METHOD

In early 2005, the literature was reviewed from 1986 to 2004 by accessing the following databases: Medline, Proquest, Science Direct, CINAHL, and Blackwell Science. The keywords mechanical ventilation, weaning, protocols, critical care, nursing role, decision-making and weaning readiness were used separately and combinations.

DISCUSSION

Controversy exists in weaning practices about appropriate and efficacious weaning readiness assessment indicators, the best method of weaning and the use of weaning protocols. Arguably, the implementation of weaning protocols may have little effect in an environment that favours collaboration between nursing and medical staff, autonomous nursing decision-making in relation to weaning practices, and high numbers of nurses qualified at postgraduate level.

CONCLUSION

Further research is required that better quantifies critical care nurses' role in weaning practices and the contextual issues that influence both the nursing role and the process of weaning from mechanical ventilation.

Methodological issues in evaluating complex healthcare interventions

AIM

This paper outlines the difficulties in defining and evaluating a complex intervention and a number of currently available models for assisting this process are discussed.

BACKGROUND

Interventions aimed at producing change in the delivery and organization of healthcare services require rigorous evaluation to demonstrate their effectiveness. Evaluation poses difficulties, however, because these interventions are usually very complex.

METHODS

A framework developed by the United Kingdom Medical Research Council to evaluate complex interventions is described. The use of this framework in designing and evaluating a nurse-led intervention in intensive care for weaning patients from mechanical ventilation is discussed. Semi-structured interviews, a questionnaire survey and observational work were undertaken to define the components of the intervention, which was subsequently evaluated in an exploratory trial using a quasi-experimental design.

CONCLUSION

The framework was a useful tool and can be easily applied in developing and evaluating complex nursing interventions. Three key challenges emerge from this experience: (i) relevant research evidence should be used systematically in developing the components of the intervention, (ii) the definition and measurement of complex intervention outcomes needs to be improved and (iii) appropriate research designs must be used when evaluating complex interventions.

Protocol-based titration of intravenous terbutaline decreases length of stay in pediatric status asthmaticus

Although frequently used to treat status asthmaticus in children, intravenous (IV) terbutaline has not been shown to decrease hospital length of stay (LOS). We theorized that this lack of demonstrable benefit resulted from variations in dosing and titration, rather than the drug per se, and that intensive care unit (ICU) LOS would be shortened by the administration of terbutaline according to a protocol incorporating a quantitative assessment of severity of illness. We prospectively treated 20 consecutive children with status asthmaticus with IV terbutaline according to a protocol that titrated the dose based on a clinical asthma score, the Modified Pulmonary Index Score (MPIS). Data were compared to a historic cohort of the previous 20 consecutive ICU patients with status asthmaticus who were treated with IV terbutaline prior to initiation of the protocol. Patients who received terbutaline by standardized protocol had significantly shorter ICU LOS (3.5 +/- 1.1 vs. 5.0 +/- 2.0 days, P = 0.01), shorter hospital LOS (5.5 +/- 1.3 vs. 8.3 +/- 2.7 days, P < 0.01), and reduced hospital charges ($19,298 +/- $10,516 vs. $26,528 +/- $12,328, P = 0.04). The method of administration of IV terbutaline significantly influenced ICU length of stay and hospital charges.

Implementing a protocol for weaning patients off mechanical ventilation

Weaning patients from ventilation can be a costly and time-consuming intervention. This article describes how a protocol was designed and introduced into the critical care unit of a district general hospital in 2003. A step-by-step approach was used based on that outlined by the Modernisation Agency and The National Institute for Clinical Excellence. The purpose of the project was to improve the weaning process in the unit by devising a protocol, which would give structure to weaning and help maintain continuity. It was hoped that the changes in practice would also reduce ventilator time and improve patient outcomes. A multi-professional group interested in weaning worked together to formulate a protocol, which was duly implemented into the unit. After implementation, the protocol was audited and subsequently adopted by the unit. Although it was agreed that the structure and the continuity of weaning had improved, reducing weaning times and patient outcomes was difficult to measure. This article explains how the protocol came to be written and how it was implemented into the unit.